Completion of wells in a plurality of formations



FIG. 3.

c. B. CORLEY, JR

Filed Oct. ,7, 1959 FIG. 2.,

J 8 I Y 5 2 3 2 R E I ..TI... ..L m IL T p A p I a p p n p n N R A 0 wl] l W C a I p a M I a .0 u r WEQ UN .vvr H Q M I E N r p f n b l 1/ R I{L M: M 4 v 6 3 2%? 2 C Y B r 5 4 Us p M l p l I w W M f p a p r/ M W li g 6 4 v I 2 1 4. 6 7 2 May 29, 1962 COMPLETION OF WELLS IN A PLURALITYOF FORMATIONS FIG.

3,fl3b,534 Patented May 29, 1962 qr a r titted States it COMPLETEGN FWELLS IN A PLURALETY @F FGRMATIONS Charles B. Carley, in, Houston, Tern,assignor, by mesne assignments, to Jersey Production Research Company,Tulsa, Okla, a corporation of Delaware Filed Oct. 7, 1959, Ser. No. 815,1966 7 Unions. (13]. 166-35) The present invention is directed to amethod for completing a well in a plurality of subsurface earthformations. More particularly, the invention is concerned with thecompletion and working over of wells having a plurality of pipe stringsarranged therein. In its more specific aspects, the invention isconcerned with completing and working over a well having a plurality ofpipe strings arranged therein, which workover and servicing operationsare conducted in only one of the pipe strings.

The present invention may be briefly described as a method forcompleting and working over a well having a first pipe string arrangedtherein penetrating a plurality of spaced apart hydrocarbon productivezones and an eccentric second pipe string connected by its lower end tothe first pipe string at a point above said zones. Two or more of thezones are perforated from one of the pipe strings and the zones are thenisolated from each other, but each zone is in fluid communication withone of the pipe strings. The lower of the zones is produced through thefirst pipe string and an upper of the zones is produced through thesecond pipe string. One of the zones is then isolated from the secondpipe string and the zone remaining in communication with the second pipestring is then worked over by flowing a fluid down the first pipe stringto the particular zone and then up the second pipe string.

After the one or more of the zones has been worked over, production maythen be resumed from a plurality of the zones.

The invention contemplates that the upper zones will be isolated fromthe second pipe string and the lower zone then worked over by flowing afluid down the first pipe string to the lower zone and up the secondpipe string. The invention also contemplates isolating the lower zonefrom the second pipe string and working over the upper zone by flowing afluid down the first pipe string to the upper zone and up the secondpipe string. Thereafter, production may be resumed.

The present invention will be further illustrated by reference to thedrawing in which FIGS. 1 to 3, inclusive, represent a stepwise preferredmode of practicing the invention.

Referring now to the drawing, which is schematic, in the method of thepresent invention, two eccentrically arranged parallel casing stringsare installed as shown in FIG. 1 with one of the casing stn'ngs 1extending through all of the productive intervals and the second casingstring 2 terminating above the uppermost productive interval and fluidlyconnected to the first casing string 1 by an interconnecting meansforming a fluid port 3. The dual casing assembly is sealed in the wellbore 4 with cement 5. Casing or pipe string 1 contains selective landingnipple 6 and polished bore nipples 7 and 8. The polished bore nipple 8may be preferably a second selective landing nipple with a polished boreto facilitate plugback, as will be described later. Perfora-tions 9 and10 are formed in zones 12 and 14, respectively, by lowering a perforatorwhich may be a bullet gun perforator, a shaped charge perforator, amechanical, or chemical perforator. Following the perforation in theformation of perforations 9 and 11}, a retrievable production tube 15provided with seal element 16 on the lower end and seal element 17 andan extension hanger 18 on its upper end is installed by lowering on awireline to isolate zones 12 and 14 as shown in the drawing. Productionfrom zone 14 is conducted through the retrievable production tube 15 andthrough the casing string 1 to the surface and through the wellheadinstalled on the well. Production from zone 12 is conducted into theannulus space 29 between retrievable production tube 15 and easingstring 1 through the fluid port 3 into the casing string 2 and then tothe surface. With this installation, separate and simultaneousproduction of hydrocarbons such as oil and gas may be obtained fromvertically spaced apart intervals and workover of either or both zonesmay be accomplished with wireline equipment, as will be describedfurther. In short, the present invention provides a dual completioninstallation which does not require orienting guns for perforatingeither zone, and the casing string 2 may be of small size onlysuflicient to conduct the hydrocarbon fluids to the wellhead since it isunnecessary to conduct workovers through the string 2.

In practicing the present invention, to permanently or temporarily plugzone 14, a plugging device may be installed in or adjacent the lower endof retrievable production tube 15 such that fluids produced from zone 14are isolated below seal 16 in landing nipple 8. The retrievableproduction tube 15 is removed from the well by a wireline, not shown,and a plug is installed in or adjacent the lower end of the productiontube 15 prior to reinstalling.

Another mode of operation is shown in FIG. 2 in which a wirelineretrievable plug 21 is installed in landing nipple 8 to seal zone 14from the casing assembly above landing nipple 8. Subsequently,production may be had from zone 12 through either or both casing stringsI and 2, as may be desired. Retrievable production tube 15 is removedprior to this work and need not be reinstalled for subsequent productionof a single productive interval.

In working over or squeeze-cementing the upper zone or treating theupper zone 12 with acids or other fluids such as surface active agentsand the like, retrievable production tube 15 is removed and -a wirelineretrievable plug 21 may be installed in landing nipple 8 to plugtemporarily zone 14. A tubular member 22 is then lowered on a wirelineand suspended from landing nipple 6 for squeeze-cementing zone 12.Circulation is accomplished through casing string 1 through tubularmember 22, annulus 2t}, fluid port 3, and upward to the earths surfacethrough casing string 2. It is apparent that circulation in the reversedirection is also possible. Following the squeeze-cementing of zone 12,tubular member 22 and the retrievable plug 21 are removed by a wireline,not shown. Zone 12 may then be reperforated or another zone per-forated,and retrievable production tube 15 may be reinstalled to obtainproduction from the two zones or intervals as previously described.

In working over the lower zone such as for squeezecementing zone 14 orfor treating it with a surface active agent or a sand consolidatingagent and the like. apparatus as shown in FIG. 3 may be employed. Inthis opera-. tion, retrievable production tube 15 is removed and aconcentric tubular member 25 which is open on both ends is installed toprovide circulation to zone 14 while simultaneously isolating zone 12from the circulating fluids. The concentric production tube or tubularmember 25 shown in FIG. 3 is provided with an inner tubular member 26and an outer tubular member 27 connected together on each end byconnecting and spacing means 26a and 27a, respectively, which providesan annulus 28 tberebetween. The outer tubular member 27 is sealed with adeformable sealing means 29 below the fluid port 3 and is sealed with adeformable sealing means 31} above the zone 14. Sealing means 29 and 30are carried on the a scess exterior of outer tubular member 27. Theinner tubular member is sealed with sealing means 31 above the fluidport 3. Following the treatment of the zone 14 as may be desired, theconcentric tubular member 25 is removed, zone 14 may be reperforated,and retrievable production tubular member 15 may be reinstalled forseparate and simultaneous production from the two intervals as has beendescribed.

In the practice of the present invention, the retrievable plug member 21may be a plug member such as has been described in Serial No, 769,343,entitled Apparatus for Use in a Well Bore, filed October 24, 1958, nowPatent No. 2,966,946.

The workover fluid employed in the present invention may suitably be lowstrength cementitious material as a slurry, acid which is used as astimulating medium, servicing fluids and consolidation agents, and otherworkover fluids such as oil-water emulsions and the like may be used.

The present invention is quite advantageous and useful in that in thepresent invention all workover operations are conducted through one ofthe casing or pipe strings while the other casing or pipe string is usedsolely for conducting fluids. In the practice of the present invention,zones may be isolated from each other without cementing perforations andall operations are conducted using wireline tools. Thus, in the practiceof the present invention, it is unnecessary to maintain heavy dutylifting equipment on the well and all operations may be conducted by aservice truck and the drilling rig may be moved away for drillinganother well.

The nature and objects of the present invention having been completelydescribed and illustrated what I wish to claim as new and useful andsecure by Letters Patent is:

1. In a well having a first pipe string arranged therein penetrating aplurality of spaced apart hydrocarbon productive zones and an eccentricsecond pipe string connected by its lower end to the first pipe stringat a point above said zone for fluid communication between said strings,the method which comprises separately perforating at least two of saidzones from said first pipe string, isolating said zones from each other,said isolated zones each being in fluid communication with one of saidpipe strings, producing a lower of said zones through a selected one ofsaid pipe strings and producing an upper of said zones through the otherof said pipe strings, isolating one of said zones from said other pipestring, the other of said zones being in fluid communication with theother of said pipe strings, and then working over said other zone byflowing fluid down said selected one pipe string and up said other pipestring.

2. A method in accordance with claim 1 in which the lower zone isproduced through the first pipe string and the upper zone is producedthrough the second pipe string.

3. In a well having a first pipe string arranged therein penetrating aplurality of spaced apart hydrocarbon productive zones and an eccentricsecond pipe string connected by its lower end to the first pipe stringat a point above said zones for fluid communication between saidstrings, the method which comprises se arately pe-rfonating at least twoof said zones from said first pipe string, isolating said zones fromeach other, said isolated zones each being in fluid communication withone of said pipe strings, producing a lower of said zones through thefirst pipe string and producing an up er of said zones through thesecond pipe string, isolating one of zones from said second pipe string,the other of said zones being in fluid communication with said secondpipe string, working over said other zone by flowing fluid down saidfirst pipe string and up said second pipe string, re-establishing fluidcommunication between said one zone and said second pipe string,isolating said zones from each other, and then resuming production froma plurality of said zones.

4. In a well having a first pipe string arranged therein penetrating aplurality of spaced apart hydrocarbon productive zones and eccentricsecond pipe string connected by its lower end to the first pipe stringat a point above said zones for fluid communication between saidstrings, the method which comprises separately perforating at least twoof said zones from said first pipe string, isolating said zone from eachother, a lower of said isolated zones being in fluid communication withthe first pipe string and an upper of said isolated zones being in fluidcommunication with the second pipe string, producing the lower of saidzones through the first pipe string and producing the upper or" saidzones through the second pipe string, isolating said upper zone fromsaid second pipe string, said lower zone being in fluid communicationwith said second pipe string, and working over said lower zone byflowing a fluid down said first pipe string and up said second pipestring.

5. In a well having a first pipe string arranged therein penetrating aplurality of spaced apart hydro-carbon productive zones and an eccentricsecond pipe string connected by its lower end to the first pipe stringat a point above said zones for fluid communication between saidstrings, the method which comprises separately perforating at least twoof said zones from said first pipe string, isolating said zones fromeach other, a lower of said isolated zones being in fiuid communicationwith the first pipe string and an upper of said zones being in fluidcommunication with the second pipe string, producing the lower of saidzones through the first pipe string and producing the upper of saidzones through the second pipe string, isolating said lower zone fromsaid second pipe string, said upper zone being in fluid communicationwith said second pipe string, and working over said upper zone byflowing a fluid down said first pipe string and up said second pipestring.

6. In a well having a first pipe string arranged therein penetrating aplurality of spaced apart hydrocarbon productive zones and an eccentricsecond pipe string connected by its lower end to the first pipe stringat a point above said zones for fluid communication between saidstrings, the method which comprises separately perforating at least twoof said zones from said first pipe string, isolating said zones fromeach other, a lower of said isolated zones being in fluid communicationwith the first pipe string and an upper of said zones being in fluidcommunication with the second pipe string, producing the lower of saidzones through the first pipe string and producing the upper of saidzones through the second pipe string, isolating said upper Zone fromsaid second pipe string, said lower zone being in fluid communicationwith said second pipe string, working over said lower zone by flowing afluid down said first pipe string and up said second pipe string,isolating said lower zone from said second pipe string, said upper zonebeing placed in fluid communication with said second pipe string, andworking over said upper zone by flowing a fluid down said first pipestring and up said second pipe string.

7. In a. well having a first pipe string arranged therein penetrating aplurality of spaced apart hydrocarbon productive zones and an eccentricsecond pipe string connected by its lower end to the first pipe stringat a point above said zones for fluid communication between saidstrings, the method which comprises separately perforating at least twoof said zones from said first pipe string, isolating said zones fromeach other, a lower of said isolated zones being in fluid communicationwith the first pipe string and an upper of said zones being in fluidcommunication with the second pipe string, producing the lower of saidzones through the first pipe string and producing the upper of saidzones through the second pipe string, isolating said upper zone fromsaid second pipe string, the lower zone being in fluid communicationwith the second pipe string, working over said lower zone by flowing afluid down said first pipe string and up 5 65 said second pipe string,isolating said lower zone from and then resuming production from aplurality of said said second pipe string, the upper zone being placedin zones. fluid communication with the second pipe string, workingReferences cu in The fil f this patent over said upper zone by flowing afluid down said first pipe string and up said second pipe string,re-establishing 5 UNITED STATES PATENTS fluid communication between saidlower zone and said 2,760,578 Tausch Aug. 28, 1956 second pipe string,isolating said zones from each other, 2,911,048 Dublm et a1. Nov. 3,1959

